Rollup merge of #138790 - xizheyin:issue-138626, r=compiler-errors

Note potential but private items in show_candidates

Closes #138626 .
We should add potential private items to give ample hints.
And for the other seemingly false positive ` pub use crate::one::Foo;` should be kept because we don't know if the user wants to import other module's items or not, and therefore should be given the full option to do so.
r? compiler

12 files changed, 135 insertions, 14 deletions

diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index d886a81b57d..6dc854758da 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1325,11 +1325,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             })
         }
 
-        // If only some candidates are accessible, take just them
-        if !candidates.iter().all(|v: &ImportSuggestion| !v.accessible) {
-            candidates.retain(|x| x.accessible)
-        }
-
         candidates
     }
 
@@ -1793,7 +1788,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 &import_suggestions,
                 Instead::Yes,
                 FoundUse::Yes,
-                DiagMode::Import { append: single_nested },
+                DiagMode::Import { append: single_nested, unresolved_import: false },
                 vec![],
                 "",
             );
@@ -2750,6 +2745,8 @@ pub(crate) enum DiagMode {
     Pattern,
     /// The binding is part of a use statement
     Import {
+        /// `true` means diagnostics is for unresolved import
+        unresolved_import: bool,
         /// `true` mean add the tips afterward for case `use a::{b,c}`,
         /// rather than replacing within.
         append: bool,
@@ -2800,6 +2797,7 @@ fn show_candidates(
         return false;
     }
 
+    let mut showed = false;
     let mut accessible_path_strings: Vec<PathString<'_>> = Vec::new();
     let mut inaccessible_path_strings: Vec<PathString<'_>> = Vec::new();
 
@@ -2958,8 +2956,11 @@ fn show_candidates(
             append_candidates(&mut msg, accessible_path_strings);
             err.help(msg);
         }
-        true
-    } else if !(inaccessible_path_strings.is_empty() || matches!(mode, DiagMode::Import { .. })) {
+        showed = true;
+    }
+    if !inaccessible_path_strings.is_empty()
+        && (!matches!(mode, DiagMode::Import { unresolved_import: false, .. }))
+    {
         let prefix =
             if let DiagMode::Pattern = mode { "you might have meant to match on " } else { "" };
         if let [(name, descr, source_span, note, _)] = &inaccessible_path_strings[..] {
@@ -3022,10 +3023,9 @@ fn show_candidates(
 
             err.span_note(multi_span, msg);
         }
-        true
-    } else {
-        false
+        showed = true;
     }
+    showed
 }
 
 #[derive(Debug)]
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 454460e10dc..0b3633a452c 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -734,7 +734,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         &mut diag,
                         Some(err.span),
                         candidates,
-                        DiagMode::Import { append: false },
+                        DiagMode::Import { append: false, unresolved_import: true },
                         (source != target)
                             .then(|| format!(" as {target}"))
                             .as_deref()
diff --git a/tests/ui/imports/glob-resolve1.stderr b/tests/ui/imports/glob-resolve1.stderr
index 75e65681c3a..23b0db0fa46 100644
--- a/tests/ui/imports/glob-resolve1.stderr
+++ b/tests/ui/imports/glob-resolve1.stderr
@@ -58,6 +58,11 @@ error[E0425]: cannot find function `import` in this scope
 LL |     import();
    |     ^^^^^^ not found in this scope
    |
+note: function `bar::import` exists but is inaccessible
+  --> $DIR/glob-resolve1.rs:7:5
+   |
+LL |     fn fpriv() {}
+   |     ^^^^^^^^^^ not accessible
 help: consider importing this function
    |
 LL + use other::import;
diff --git a/tests/ui/imports/issue-4366-2.stderr b/tests/ui/imports/issue-4366-2.stderr
index 412423f4d59..b1c0092b05d 100644
--- a/tests/ui/imports/issue-4366-2.stderr
+++ b/tests/ui/imports/issue-4366-2.stderr
@@ -16,6 +16,11 @@ error[E0423]: expected function, found module `foo`
 LL |     foo();
    |     ^^^ not a function
    |
+note: function `m1::foo` exists but is inaccessible
+  --> $DIR/issue-4366-2.rs:21:5
+   |
+LL |     fn foo() {}
+   |     ^^^^^^^^ not accessible
 help: consider importing this function instead
    |
 LL + use foo::foo;
diff --git a/tests/ui/imports/issue-4366.stderr b/tests/ui/imports/issue-4366.stderr
index e63399d554e..54b7f31b231 100644
--- a/tests/ui/imports/issue-4366.stderr
+++ b/tests/ui/imports/issue-4366.stderr
@@ -4,6 +4,11 @@ error[E0425]: cannot find function `foo` in this scope
 LL |         fn sub() -> isize { foo(); 1 }
    |                             ^^^ not found in this scope
    |
+note: function `m1::foo` exists but is inaccessible
+  --> $DIR/issue-4366.rs:23:5
+   |
+LL |     fn foo() {}
+   |     ^^^^^^^^ not accessible
 help: consider importing this function
    |
 LL +         use foo::foo;
diff --git a/tests/ui/imports/show-private-items-issue-138626.rs b/tests/ui/imports/show-private-items-issue-138626.rs
new file mode 100644
index 00000000000..d9708fc33c2
--- /dev/null
+++ b/tests/ui/imports/show-private-items-issue-138626.rs
@@ -0,0 +1,19 @@
+pub mod one {
+    mod foo {
+        pub struct Foo;
+    }
+
+    pub use self::foo::Foo;
+}
+
+pub mod two {
+    mod foo {
+        mod bar {
+            pub struct Foo;
+        }
+    }
+
+    pub use crate::two::foo::Foo; //~ ERROR unresolved import `crate::two::foo::Foo` [E0432]
+}
+
+fn main() {}
diff --git a/tests/ui/imports/show-private-items-issue-138626.stderr b/tests/ui/imports/show-private-items-issue-138626.stderr
new file mode 100644
index 00000000000..b664462daed
--- /dev/null
+++ b/tests/ui/imports/show-private-items-issue-138626.stderr
@@ -0,0 +1,20 @@
+error[E0432]: unresolved import `crate::two::foo::Foo`
+  --> $DIR/show-private-items-issue-138626.rs:16:13
+   |
+LL |     pub use crate::two::foo::Foo;
+   |             ^^^^^^^^^^^^^^^^^^^^ no `Foo` in `two::foo`
+   |
+note: struct `two::foo::bar::Foo` exists but is inaccessible
+  --> $DIR/show-private-items-issue-138626.rs:12:13
+   |
+LL |             pub struct Foo;
+   |             ^^^^^^^^^^^^^^^ not accessible
+help: consider importing this struct through its public re-export instead
+   |
+LL -     pub use crate::two::foo::Foo;
+LL +     pub use one::Foo;
+   |
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0432`.
diff --git a/tests/ui/privacy/privacy-ns1.stderr b/tests/ui/privacy/privacy-ns1.stderr
index 3396330c993..c782c67e71c 100644
--- a/tests/ui/privacy/privacy-ns1.stderr
+++ b/tests/ui/privacy/privacy-ns1.stderr
@@ -7,6 +7,14 @@ LL |     pub struct Baz;
 LL |     Bar();
    |     ^^^
    |
+note: these functions exist but are inaccessible
+  --> $DIR/privacy-ns1.rs:14:5
+   |
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo1::Bar`: not accessible
+...
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo3::Bar`: not accessible
 help: a unit struct with a similar name exists
    |
 LL -     Bar();
@@ -26,6 +34,14 @@ LL |     pub struct Baz;
 LL |     Bar();
    |     ^^^
    |
+note: these functions exist but are inaccessible
+  --> $DIR/privacy-ns1.rs:14:5
+   |
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo1::Bar`: not accessible
+...
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo3::Bar`: not accessible
 help: a unit struct with a similar name exists
    |
 LL -     Bar();
@@ -45,6 +61,14 @@ LL |     pub struct Baz;
 LL |     let _x: Box<Bar>;
    |                 ^^^
    |
+note: these traits exist but are inaccessible
+  --> $DIR/privacy-ns1.rs:25:5
+   |
+LL |     trait Bar {
+   |     ^^^^^^^^^ `foo2::Bar`: not accessible
+...
+LL |     trait Bar {
+   |     ^^^^^^^^^ `foo3::Bar`: not accessible
 help: a struct with a similar name exists
    |
 LL -     let _x: Box<Bar>;
diff --git a/tests/ui/privacy/privacy-ns2.stderr b/tests/ui/privacy/privacy-ns2.stderr
index ac98682b2b3..fe1f0c9bd48 100644
--- a/tests/ui/privacy/privacy-ns2.stderr
+++ b/tests/ui/privacy/privacy-ns2.stderr
@@ -4,6 +4,14 @@ error[E0423]: expected function, tuple struct or tuple variant, found trait `Bar
 LL |     Bar();
    |     ^^^ not a function, tuple struct or tuple variant
    |
+note: these functions exist but are inaccessible
+  --> $DIR/privacy-ns2.rs:14:5
+   |
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo1::Bar`: not accessible
+...
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo3::Bar`: not accessible
 help: consider importing this function instead
    |
 LL + use foo2::Bar;
@@ -18,6 +26,14 @@ LL |     pub struct Baz;
 LL |     Bar();
    |     ^^^
    |
+note: these functions exist but are inaccessible
+  --> $DIR/privacy-ns2.rs:14:5
+   |
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo1::Bar`: not accessible
+...
+LL |     fn Bar() { }
+   |     ^^^^^^^^ `foo3::Bar`: not accessible
 help: a unit struct with a similar name exists
    |
 LL -     Bar();
@@ -34,6 +50,14 @@ error[E0573]: expected type, found function `Bar`
 LL |     let _x : Bar();
    |              ^^^^^ not a type
    |
+note: these traits exist but are inaccessible
+  --> $DIR/privacy-ns2.rs:31:5
+   |
+LL |     trait Bar {
+   |     ^^^^^^^^^ `foo2::Bar`: not accessible
+...
+LL |     trait Bar {
+   |     ^^^^^^^^^ `foo3::Bar`: not accessible
 help: use `=` if you meant to assign
    |
 LL -     let _x : Bar();
diff --git a/tests/ui/resolve/issue-21221-1.stderr b/tests/ui/resolve/issue-21221-1.stderr
index ccf03afaa19..dafa41bf312 100644
--- a/tests/ui/resolve/issue-21221-1.stderr
+++ b/tests/ui/resolve/issue-21221-1.stderr
@@ -19,6 +19,17 @@ error[E0412]: cannot find type `Mul` in this scope
 LL | fn getMul() -> Mul {
    |                ^^^ not found in this scope
    |
+note: these items exist but are inaccessible
+  --> $DIR/issue-21221-1.rs:10:5
+   |
+LL |     enum Mul {
+   |     ^^^^^^^^ `mul3::Mul`: not accessible
+...
+LL |     type Mul = String;
+   |     ^^^^^^^^^^^^^^^^^^ `mul4::Mul`: not accessible
+...
+LL |     struct Mul{
+   |     ^^^^^^^^^^ `mul5::Mul`: not accessible
 help: consider importing one of these traits
    |
 LL + use std::ops::Mul;
diff --git a/tests/ui/unresolved/unresolved-import.rs b/tests/ui/unresolved/unresolved-import.rs
index 763e9496734..b0fdcf97015 100644
--- a/tests/ui/unresolved/unresolved-import.rs
+++ b/tests/ui/unresolved/unresolved-import.rs
@@ -31,6 +31,8 @@ mod food {
 
     mod zug {
         pub mod baz {
+        //~^ NOTE module `food::zug::baz` exists but is inaccessible
+        //~| NOTE not accessible
             pub struct Foobar;
         }
     }
diff --git a/tests/ui/unresolved/unresolved-import.stderr b/tests/ui/unresolved/unresolved-import.stderr
index c65fe841001..4001695459a 100644
--- a/tests/ui/unresolved/unresolved-import.stderr
+++ b/tests/ui/unresolved/unresolved-import.stderr
@@ -26,6 +26,12 @@ LL | use food::baz;
    |     |     |
    |     |     help: a similar name exists in the module: `bag`
    |     no `baz` in `food`
+   |
+note: module `food::zug::baz` exists but is inaccessible
+  --> $DIR/unresolved-import.rs:33:9
+   |
+LL |         pub mod baz {
+   |         ^^^^^^^^^^^ not accessible
 
 error[E0432]: unresolved import `food::beens`
   --> $DIR/unresolved-import.rs:19:12
@@ -37,13 +43,13 @@ LL | use food::{beens as Foo};
    |            help: a similar name exists in the module: `beans`
 
 error[E0432]: unresolved import `MyEnum`
-  --> $DIR/unresolved-import.rs:44:9
+  --> $DIR/unresolved-import.rs:46:9
    |
 LL |     use MyEnum::*;
    |         ^^^^^^ help: a similar path exists: `self::MyEnum`
 
 error[E0432]: unresolved import `Enum`
-  --> $DIR/unresolved-import.rs:55:9
+  --> $DIR/unresolved-import.rs:57:9
    |
 LL |     use Enum::*;
    |         ^^^^ help: a similar path exists: `self::Enum`